W Economic sectors > W.06 Manufacturing industries > W.06.06 Oil industry > Petroleum trading

W Economic sectors > W.06 Manufacturing industries > W.06.06 Oil industry > Oil industry > Petroleum trading

... > V Economics > V.12 Environmental and resource economics > V.12.02 Energy economics > Energy sector > Oil industry > Petroleum trading

... > W Economic sectors > W.22 Public sector > Public utilities > Energy sector > Oil industry > Petroleum trading

... > W Economic sectors > W.04 Energy and Water Industries > W.04.01 Energy sector > Energy sector > Oil industry > Petroleum trading

W Economic sectors > W.10 Trade > W.10.04 Trade in commodities and used materials > Petroleum trading